Author

# Angelina Markina

Bio: Angelina Markina is an academic researcher from Kazan Federal University. The author has contributed to research in topics: Microstrip antenna & Microstrip. The author has an hindex of 4, co-authored 14 publications receiving 45 citations.

##### Papers

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01 Sep 2020TL;DR: It is shown that the method of moments implementation by graphical processor provides a sufficient gain in the performance.

Abstract: In the present paper the problem of plane electromagnetic wave diffraction by a thin metal plate is considered. A numerical algorithm is developed using method of moments with NVIDIA CUDA technology implementation. The results of numerical modeling of a plane wave diffraction by the square thin metallic plate is shown. Comparative analysis of the performance for CPU and GPU is carried out. It is shown that the method of moments implementation by graphical processor provides a sufficient gain in the performance.

6 citations

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TL;DR: In this paper, the Laplace operator is used to find the expansion coefficients of the longitudinal components of the electric and magnetic intensity vectors of a cylindrical metal waveguide with a source located in the cross section.

Abstract: The problem of excitation of a cylindrical metal waveguide by a source
located in the cross section is considered. We assume that the source is surface
currents on a flat, infinitely thin metal plate with a smooth boundary. The plate
is connected to the generator of non-harmonic oscillations. The boundary of
the cross section of a waveguide filled with a homogeneous dielectric is a closed
piecewise-smooth contour. The initial physical problem is formulated as a mixed
boundary problem for the system of the Maxwell equations. Components of the
desired solution for the problem is presented in the form of a series in two sets
of two-dimensional eigenfunctions of the Laplace operator. The first set of the
eigenfunctions corresponds to the operator with Dirichlet boundary conditions,
the second set to the operator with Neumann boundary conditions. We show
that the expansion coefficients of the longitudinal components (components
directed along the waveguide axis) of the electric and magnetic intensity vectors
must be solutions to the jump problem for a system of telegraph equations. The
problem of finding the unknown coefficients of the expansion of the longitudinal
component of the vector of electric intensity is reduced to solving a system of
the Volterra integral equations of the first kind with respect to the derivatives
of the desired coefficients. The unknown coefficients of the expansion of the
longitudinal component of the vector of magnetic intensity are found by solving
a system of the Volterra integral equations of the second kind.

3 citations

12 Dec 2017

TL;DR: In this paper, the problem of excitation of electromagnetic oscillations in a waveguide with metal walls, which has an arbitrary cross-section, is reduced to an infinite set of boundary-value problems for telegraph equations in a quarter of the plane.

Abstract: The problem of excitation of electromagnetic oscillations in a waveguide with metal walls, which has an arbitrary cross-section, is reduced to an infinite set of boundary-value problems for telegraph equations in a quarter of the plane. The values of the longitudinal components of the field or of the lateral components of the magnetic vector (surface currents) on the cross-section of the waveguide can be chosen as the wave sources. It is preliminary shown that the components of the non-harmonic electromagnetic field in the waveguide are expanded into series by two sets of eigen functions of the two-dimensional Laplacian that satisfy the Neumann or Dirichlet boundary conditions. The coefficients of these expansions are the solutions of telegraph equations or derivatives of these solutions. The boundary-value problem for the telegraph equation in a quarter of the plane is considered. It has been established which boundary conditions are sufficient for determining its unique solution. The solvability conditions of the auxiliary over-determined boundary-value problem have been written down. The formulas that give an explicit solution of the telegraph equation in a quarter of the plane in the case of different boundary conditions have been obtained. It is shown how to determine the boundary values of the solutions of the telegraph equations for various types of sources of the electromagnetic field. As an example, the longitudinal components of the field for the high mode of a rectangular waveguide for given pulse sources are determined numerically.

3 citations

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TL;DR: Numerical results are presented for the problem of diffraction by a rectangular screen, as well as by screen octagonal shape and the analysis shows that the method of moments implementation by GPU significantly improves the performance of the algorithm for solving theproblem of electromagnetic wave Diffraction by the flat metal screens.

Abstract: The problem of electromagnetic wave diffraction by a flat convex screen of arbitrary shape is considered. The numerical solution for the problem is obtained by the method of moments using the parallel programming technology CUDA. As basic and testing functions RWG functions are used. To construct the corresponding RWG elements on CUDA, a simple and fast algorithm of triangulation for a convex screen with an arbitrary boundary is developed. Numerical results are presented for the problem of diffraction by a rectangular screen, as well as by screen octagonal shape. The results obtained for the rectangle are in good correspondence with the results published in previous works. A comparative analysis of the running time of sequential and parallel algorithms is presented. The analysis shows that the method of moments implementation by GPU significantly improves the performance of the algorithm for solving the problem of electromagnetic wave diffraction by the flat metal screens.

2 citations

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06 Jan 2019TL;DR: In this paper, the influence of the main geometric parameters of the antenna on the base frequency is investigated, including length and width of the radiator, depth of the rectangular cutouts on its radiator, thickness of the substrate, length of the ground and widths of the feedline, where the root-mean-square error and the relative error of these models are calculated.

Abstract: A symmetrical microstrip six-tooth-shaped antenna is considered. The influence of the main geometric parameters of the antenna on the base frequency is investigated. The main geometric parameters of the antenna include length and width of the radiator, depth of the rectangular cutouts on its radiator, thickness of the substrate, length of the ground and width of the feedline. Regression analysis is carried out and several mathematical models are constructed. The first model describes a relationship of the base frequency with depth of the rectangular cutouts, the radiator length and width. The second model describes a relationship between the wavelength at the base frequency and the geometry of the radiator. The root-mean-square error and the relative error of these models are calculated. For the base frequency and wavelength, graphs of dependencies on the geometric parameters of the antenna are plotted. We establish that a decrease in values of the base frequency and an increase in the wavelength is associated with an increase in the depth of cutouts and the radiator length. We show that a slight influence on the base frequency is caused by changes in width of the feedline, thickness of the substrate and length of the ground. The proposed formulas, describing relationships of the base frequency as well as the wavelength at this frequency with the geometric parameters of the antenna, can be used to design a six-tooth-shaped antenna in a wide frequency range.

2 citations

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[...]

TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

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TL;DR: In this article, a corrugated microstrip (CM) line is employed as the resonating part of the antenna to achieve good radiating behavior and low profile simultaneously, and the measured results show that the proposed antenna can achieve a beamwidth of 70° in E-plane and 75° in H-plane with a gain tolerance of 3 dB.

Abstract: We present a new method to design miniaturized antennas using a corrugated microstrip (CM) line, which shows good slow wave characteristic in the required frequency band. To achieve good radiating behavior and low profile simultaneously, CM is employed as the resonating part of the antenna. The impact of the CM propagation constant on the antenna is discussed in detail. The miniaturized antenna is designed and measured to verify the feasibility of the design method. The measured results show that the proposed antenna can achieve a beamwidth of 70° in E-plane and 75° in H-plane with a gain tolerance of 3 dB, and the realized peak gain level at the central frequency is 5.15 dBi, which have good agreements to the expected designs. Such results indicate that the proposed antenna exhibits excellent radiation characteristics at the resonant mode. The effective size of the proposed miniaturized antenna is $0.16\lambda _{0}\times 0.16 \lambda _{0}\times 0.04 \lambda _{0}$ at 9 GHz, in which $\lambda _{0}$ is the wavelength of the central frequency.

35 citations

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04 Jun 2020

TL;DR: In this article, the dependence of the base frequency and the reflection coefficient on the dipole wire length and scale is analyzed, and it is shown that it is possible to distinguish a family of antennas operating at a given (identical) base frequency.

Abstract: Koch-type wire dipole antennas are considered herein. In the case of a first-order prefractal, such antennas differ from a Koch-type dipole by the position of the central vertex of the dipole arm. Earlier, we investigated the dependence of the base frequency for different antenna scales for an arm in the form of a first-order prefractal. In this paper, dipoles for second-order prefractals are considered. The dependence of the base frequency and the reflection coefficient on the dipole wire length and scale is analyzed. It is shown that it is possible to distinguish a family of antennas operating at a given (identical) base frequency. The same length of a Koch-type curve can be obtained with different coordinates of the central vertex. This allows for obtaining numerous antennas with various scales and geometries of the arm. An algorithm for obtaining small antennas for Wi-Fi applications is proposed. Two antennas were obtained: an antenna with the smallest linear dimensions and a minimum antenna for a given reflection coefficient.

14 citations

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01 Feb 2019

TL;DR: The problem of fast designing of a well-matched symmetrical four-tooth-shaped microstrip antenna at frequency of 2.44 GHz is considered and regression models for wavelength, resistance and bandwidth are used to solve the problem.

Abstract: The problem of fast designing of a well-matched symmetrical four-tooth-shaped microstrip antenna at frequency of 2.44 GHz is considered. To solve the problem, we use regression models for wavelength, resistance and bandwidth. The optimization problem for finding the geometrical parameters of the antenna radiator is formulated by using these models. In the first step of approximation, the antenna is obtained as a solution to the optimization problem. In the next step, the geometry of the radiator is refined so as the base frequency of the antenna is closer to 2.44 GHz.

9 citations

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01 Jan 2018

TL;DR: In this article, the influence of the base geometric parameters of the antenna on the bandwidth at the base frequency was studied and the regression analysis was carried out and the mathematical model describing the dependence of the bandwidth on the length and the width of the radiator and the depth of the cuts was developed.

Abstract: The microstrip antenna with a symmetrical rectangular radiator and four teeth is described. The influence of the base geometric parameters of the antenna on the bandwidth at the base frequency was studied. The following geometric parameters of the antenna are selected: the length and the width of the radiator, the depth of cuts, the thickness of the substrate, the length of the ground plane and the width of the feed line. The regression analysis was carried out and the mathematical model describing the dependence of the bandwidth on the length and the width of the radiator and the depth of the cuts was developed. The rootmean-square error and the relative absolute error of the model were calculated. The graphs of the bandwidth dependences on the geometric parameters are presented. It was established that the decrease of the bandwidth values is associated with an increase of the radiator width and the substrate thickness. It was shown that a slight influence on the bandwidth are made by the changes of the radiator length and the depths of the cuts only in the case when the radiator width is much smaller than its length. The proposed formula describing the relationship of the bandwidth with the geometric parameters of the antenna can be used to design a four-tooth antenna with wide bandwidth.

9 citations